This invention relates to a control system of the interstand tension of a continuous rolling mill, more particularly of the type comprising an edger mill and a horizontal mill (a universal mill in the case of rolling shape steels) such as a rougher rolling stand of a hot strip mill and a shape steel rolling mill.
The interstand tension of a continuous rolling mill, for example, a finishing mill of a hot strip is automatically controlled to the desired value by detecting the interstand tension by a looper, for example, and by using the detected interstand tension to control the driving motors of the mill. However, in the continuous mill such as the rougher rolling stand of a hot strip mill and a shape steel rolling mill as the gauge of the strip is large it is difficult to form a loop so that use of the looper is not possible. Accordingly, the operator of the mill controls the interstand tension by manually controlling the speed of the mill drive motors while observing the strip being rolled.
With this system, however, it has been impossible to provide an adequate control by the misoperation of the operator or lack of skill thereof.